… blog: 5 subtle ways you’re using MySQL as a queue, and why it’ll bite you. Go there to read… in building a good job queue or batch processing system, and try not to create one inside MySQL. Although the job queue is a great… well in a relational database. However, experience shows me that job queues sneak up in unexpected ways, even if you’re a…
Post: Performance impact of complex queries
January 17, 2007 By 11 Comments
… on large data sets(ie some large aggregate queries) and batch jobs. It is not rare to see queries which were taking… hit the disk, which may be 100% busy running your batch job query. This is especially bad when you only have one… cases I’ve seen average time requests spends in the queue to be over 1 second, which is much more than…
Post: Living with backups
November 6, 2008 By 28 Comments
Everyone does backups. Usually it’s some nightly batch job that just dumps all MySQL tables into a text file …, etc.) that can be done with: # cat /sys/block/sd?/queue/scheduler noop anticipatory [deadline] cfq noop anticipatory [deadline] cfq noop… /sys/block/$device/queue/scheduler ] ; then \ echo “cfq” > /sys/block/$device/queue/scheduler ; fi ; done # cat /sys/block/sd?/queue/scheduler noop anticipatory…
Post: Using LoadAvg for Performance Optimization
December 4, 2006 By 5 Comments
… are no performance problems, for example if you run single batch job on the server with MySQL, Load Average is likely to… increase mainly because of time requests spend waiting in various queues and waiting on locks, the time of true execution may… understand where parallel execution continues and where waiting in the queue starts. If you have fully CPU bound workload which is…
Post: Queries Active vs Transactions Active
September 14, 2009 By Leave a Comment
…STATUS): ————– ROW OPERATIONS ————– 8 queries inside InnoDB, 9 queries in queue 100 read views open inside InnoDB It is relationship between… often in the processlist, which often corresponds to some long batch jobs, sometimes you would just see the processlist showing connection is…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…: No PZ: Another possible area of optimization. I frequently see batch jobs killing server performance overtaking buffer pool. Though full table scan… once. Q12: If read-ahead request was placed to the queue but did not start executing yet will innodb has to…
